Warming Climate Is Changing Life On A Global Scale
by Staff Writers
New York NY (SPX) May 19, 2008
A vast array of physical and biological systems across
the earth are being affected by warming temperatures
caused by humans, says a new analysis of information
not previously assembled all in one spot.
The effects on living things include earlier leafing of
trees and plants over many regions; movements of
species to higher latitudes and altitudes in the northern
hemisphere; changes in bird migrations in Europe,
North America and Australia; and shifting of the
oceans' plankton and fish from cold- to warm-adapted
communities.
Figure 1 Changes include wastage of
glaciers on all continents; melting
permafrost; earlier spring river runoff; and
warming of water bodies. Among living
creatures inhabiting such systems, 90% of
changes are consistent with warming.
"Humans are influencing climate through increasing
greenhouse gas emissions, and the warming world is
causing impacts on physical and biological systems
attributable at the global scale," said lead author Cynthia Rosenzweig, a scientist at the NASA
Goddard Institute for Space Studies and the Columbia Center for Climate Systems Research.
Both are affiliates of The Earth Institute at Columbia University.
Rosenzweig and researchers from 10 other institutions across the world analyzed data from
published papers on 829 physical systems and some 28,800 plant and animal systems, stretching
back to 1970. Their analysis of revealed a picture of changes on continental scales; previous
studies had looked mainly at single phenomena, or smaller areas. In physical systems, 95% of
observed changes are consistent with warming trends.
These include wastage of glaciers on all continents; melting permafrost; earlier spring river
runoff; and warming of water bodies. Among living creatures inhabiting such systems, 90% of
changes are consistent with warming.
The researchers say it is unlikely that any force but human-influenced climate change could be
driving all this; factors like deforestation or natural climate variations could not explain it. Their
work builds upon the consensus of the Intergovernmental Panel on Climate Change, which in
2007 declared manmade climate warming "likely" to have discernible effects on biological and
physical systems.
"It was a real challenge to separate the influence of human-caused temperature increases from
natural climate variations or other confounding factors, such as land-use changes or pollution,"
said coauthor David Karoly, a climate scientist at the University of Melbourne in Victoria,
Australia.
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"This was possible only through the combined efforts of our multi-disciplinary team, which
examined observed changes in many different systems around the globe, as well as global
climate model simulations of temperature changes."
The data showing the patterns of change are strongest in North America, Asia and Europe-mainly because far more studies have been done there, said Rosenzweig. On the other continents,
including South America, Australia and Africa, documentation of changes in physical and
biological systems is sparse, even though there is good evidence there of human-influenced
warming itself.
The authors say that there is an urgent need to study these environmental systems, especially in
tropical and subtropical areas.
***
Earth Impacts Linked To Human-Caused Climate Change
by Staff Writers
Greenbelt MD (SPX) May 19, 2008
A new NASA-led study shows that human-caused
climate change has impacted a wide range of Earth's
natural systems, from permafrost thawing to plants
blooming earlier across Europe to lakes declining in
productivity in Africa.
Cynthia Rosenzweig of NASA's Goddard Institute for
Space Science in New York and scientists at 10 other
institutions have linked physical and biological
impacts since 1970 with rises in temperatures during
that period. The study, published May 15 in the
journal Nature, concludes that human-caused warming
is resulting in a broad range of impacts across the
globe.
Figure 2 Areas of significant changes to
Earth systems observed in North America
over the last 20 years, represented by
various symbols, are linked with areas of
rising temperatures, noted in red. Credit:
NASA
"This is the first study to link global temperature data
sets, climate model results, and observed changes in a broad range of physical and biological
systems to show the link between humans, climate, and impacts," said Rosenzweig, lead author
of the study.
Rosenzweig and colleagues also found that the link between human-caused climate change and
observed impacts on Earth holds true at the scale of individual continents, particularly in North
America, Europe, and Asia.
To arrive at the link, the authors built and analyzed a database of more than 29,000 data series
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pertaining to observed impacts on Earth's natural systems, collected from about 80 studies each
with at least 20 years of records between 1970 and 2004. Observed impacts included changes to
physical systems, such as glaciers shrinking, permafrost melting, and lakes and rivers warming.
Impacts also included changes to biological systems, such as leaves unfolding and flowers
blooming earlier in the spring, birds arriving earlier during migration periods, and ranges of plant
and animal species moving toward the poles and higher in elevation. In aquatic environments
such as oceans, lakes, and rivers, plankton and fish are shifting from cold-adapted to warmadapted communities.
The team conducted a "joint attribution" study in which they showed, first, that at the global
scale, about 90 percent of observed changes in diverse physical and biological systems are
consistent with warming. Other driving forces, such as land use change from forest to
agriculture, were ruled out as having significant influence on the observed impacts.
Next, the scientists conducted statistical tests and found that the spatial patterns of observed
impacts closely match temperature trends across the globe, to a degree beyond what can be
attributed to natural variability. So, the team concluded that observed global-scale impacts are
very likely due to human-caused warming.
"Humans are influencing climate through increasing greenhouse gas emissions and the warming
is causing impacts on physical and biological systems that are now attributable at the global scale
and in North America, Europe, and Asia," said Rosenzweig.
On other continents, including Africa, South America, and Australia, documentation of observed
changes in physical and biological systems is still sparse despite warming trends attributable to
human causes. The authors concluded that environmental systems on these continents need
additional research, especially in tropical and subtropical areas where there is a lack of impact
data and published studies.
*** NOTICE: In accordance with Title 17 U.S.C. Section 107, this material is distributed,
without profit, for research and educational purposes only. ***
Both articles are from Terra Daily online.
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